Release mechanism for meter-type relays



1, 1956 T. J. PETHES 2,760,125

RELEASE MECHANISM FOR METER-TYPE RELAYS Filed Aug. 7, 1951 44 FIG. /2

#wnvrafi- 7.11 I ETHES United States Patent RELEASE NIECHANISM FOR METER-TYPE RELAYS Theodore J. Pethes, Elmwood Park, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application August 7, 1951, Serial No. 240,753

3 Claims. (Cl. 317-152) This invention relates to meter-type relays having magnetic contacts and more particularly to a mechanism for releasing the contact arm from the magnetic contact of a meter-type relay after it has been actuated.

It is common practice in some designs of meter-type relays to provide magnetic contacts for cooperation with a magnetizable member on the contact arm to magnetically attract and maintain the contact arm in actuated position, and when such magnetic contacts are used mechanism is generally provided for releasing the contact arm from engagement with the magnetic contact and restoring it to its normal disengaged position. The mechanism is usually in the form of one or a pair of arms which are electrically actuated to engage the contact arm and mechanically return it to its neutral or inoperative position. However, because of the speed at which the arms are actuated, and because of the frailness of the contact arms, the contact arms are frequently bent out of shape and the relays rendered inoperative and the contact arms are worn through due to the impact and sliding action of the restoring arms.

It is an object of the present invention to provide an improved mechanism for releasing the contact arm from magnetic contacts in a meter-type relay.

In accordance with one embodiment of the invention, a meter-type relay is provided with a magnetic contact slidably mounted within a non-magnetic tube and yieldably maintained in a normal forward position with an end portion thereof extending beyond the tube for engagement with a magnetizable member on the contact arm for magnetically holding the contact arm in operative position in response to the actuation of the relay. A solenoid encircling the non-magnetic tube is eonnectible, automatically or under control of the operator, to a source of current to energize the solenoid and effect the retraction of the magnetic contact and the separation thereof from the contact arm, thus permitting the contact arm to be returned to its normal inoperative position by the action of its torque control springs.

Other objects and advantages of the invention will become apparent by reference to the following detailed description thereof when considered in conjunction with the accompanying drawings illustrating a preferred embodiment thereof, in which Fig. 1 is a somewhat diagrammatic plan view of a meter-type relay; and

Fig. 2 is an enlarged sectional view through one of the magnetic contacts and the solenoid for retracting it and showing the contact in its retracted position.

Referring to Fig. 1 of the drawings, there is shown a meter-type relay comprising a permanent magnet 10 mounted on a base 12 and having a movable system including a coil 14 and a contact arm 16 mounted for movement with the coil. The coil 14 is connected to a control circuit 20, and in response to the flow of current therethrough of a predetermined value in either direction, the contact arm 16 is caused to move into close proximity to one or the other of a pair of magnetic con- 2,760,125 Patented Aug. 21, 1956 ice tacts 25 and is then magnetically attracted thereto and forcibly held in contact therewith to complete a circuit through the contact arm 16, either one of the contacts 25, and conductors 23-23 connected thereto. The contact arm 16 is yieldably maintained in and returned to its normal inoperative or neutral position by any suitable means such as the conventional spiral springs 27.

The contacts 25 each comprise a contact element 28 of magnetic material which is magnetized to form a permanent magnet and is mounted within a tubular member 29 of non-magnetic material, for movement from '2. normal forward position shown in Fig. 1 to a retracted position shown in Fig. 2. The forward end 30 of the tube 29 is bent inwardly to form a shoulder which limits the forward movement of the contact element and provides an aperture through which the reduced end 31 of the contact element 28 extends. The magnetic contact 28 is adapted to engage a magnetizable element or rider 32 on the contact arm 16 when the relay has been actuated and acts to magnetically hold the contact arm 16 in its actuated position. A spring 33 within the tube 29 serves to yieldably maintain the magnetic contact 28 in and return it to its forward position.

When it is desired to release the contact arm 16 and interrupt the controlled circuit through the conductors 23, the contact element 28 may be moved to its retracted position (Fig. 2) to cause the end 31 thereof to be withdrawn within the tube 29 and cause it to become disengaged from the magnetizable member 32 on the contact arm 16, which is then free to be returned to its normal inoperative position under the influence of the spring 27. Solenoids 40 mounted on the base 12 encircle portions of the non-magnetic tube 29 and support them in fixed positions. The solenoids are connected to a source of current 42 through a manually or mechanically operated switch 44, which when closed will cause the energization of the solenoids, and eifect the retraction of the magnetic contact elements 28 which form the armatures of the solenoids. During the movement of the contact element 28 to its retracted position, the magnetizable member 32 and the contact arm 16 are moved a short distance with the contact element 28 until the member 32 engages the end 30 of the tube 29, which arrests further movement of the contact arm 16 and as the contact element 28 continues its movement it separates from the magnetizable member 32, and when the contact element 28 reaches its retracted position as shown in Fig. 2, the magnetic attraction thereof is reduced to the point where it can no longer hold the contact arm 16 in operative position, and the contact arm then is returned to its normal neutral position shown in Fig. 1 by the control spring 27.

Thus, in the operation of this device after the relay has been actuated to cause the magnetizable member 32 of the contact arm 16 to engage and be magnetically held in contact with the magnetic contact element 28 to complete a circuit through the conductors 23, when it is desired to interrupt the circuit and release the contact arm 16, the switch 44 is closed, causing the retraction of the magnetic contact elements 28 and their disengagement from the contact arm 16.

While each of the movable magnetic contact elements 28 is disclosed as being mounted for movement in the general direction of the movement of the member 32 on the contact arm 16 and is separated or released from the member 32 by the cooperation of the end 30 of the tubes 29, which serves to stop the member 32 as the magnetic contact element 28 continues its movement to its retracted position, the contact member 28 may be mounted for movement in other directions relative to the member 32 on the contact arm 16 such as, for instance, movement transversely to and out of the path of'movement of the member 32. Likewise, the mechanism for actuating the magnetic contact element 28 may be mechanical as well as electro-magnetic.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. In a meter-type relay having a movable system including a contact arm, the combination therewith of a magnetizable element on said contact arm, a magnetic contact, a non-magnetic tubular member supporting said magnetic contact in the path of movement of the magnetizable element for engagement therewith and for movement in a direction longitudinally of the path of movement of said magnetizable element to and from a normal advanced position and a retracted position, means yieldably maintaining said magnetic contact in said advanced position, and an electro-magnetic coil encircling said tubular member and having a magnetic field efiective to move said magnetic contact to its retracted position in response to energization thereof, means for energizing and deenergizing said coil, said non-magnetic member forming a stop engageable with said contact arm for preventing the magnetizable element from moving with said magnetic contact to its retracted position.

2. In a meter type relay having a movable contact arm, the combination therewith of a first magnetizable contact on said contact arm, a stationary solenoid mounted in the path of movement of said first contact and including an armature forming a second magnetizable contact engageable with said first contact, one of said contacts being magnetized to form a permanent magnet, a non-magnetic tubular member for guiding said second contact to and from an advanced position and a retracted position and having an end portion with an aperture therein for limiting the movement of said second contact in one direction to said advanced position and for limiting the movement of said first contact in the opposite direction, said second contact having a portion extending through said aperture in the tubular member when in said advanced position for engaging said first contact, resilient means for moving said second contact to said advanced position, and an electromagnetic coil encircling said tube and operable in response to energization thereof for electromagnetically moving said second contact to said retracted position in spaced relation to said end portion of the tubular member to disengage the second contact from said first contact.

3. In a meter-type relay having a movable contact arm with a magnetizable contact thereon, a permanent magnet contact, means for mounting the permanent magnet contact in the path of movement of the magnetizable contact and for movement longitudinally of said path of movement of said magnetizable contact to and from a normal advanced position and a retracted position, said permanent magnet contact in its advanced position being engageable with the magnetizable contact on said contact arm, means yieldably maintaining said permanent magnet contact in said advanced position, an electro-magnetic coil having a magnetic field encompassing said permanent magnet contact for moving said permanent magnet contact to its retracted position, and means for energizing and deenergizing said coil, stop means engageable with the contact arm for preventing the magnetizable contact from moving with the permanent magnet contact to is reracted position to effect the release of the contact arm when the permanent magnet contact is moved to its retracted position.

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